Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
  • B41M5/3858—Mixtures of dyes, at least one being a dye classifiable in one of groups B41M5/385 - B41M5/39
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
  • B41M5/3852—Anthraquinone or naphthoquinone dyes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/382—Contact thermal transfer or sublimation processes
  • B41M5/385—Contact thermal transfer or sublimation processes characterised by the transferable dyes or pigments
  • B41M5/388—Azo dyes
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/913—Material designed to be responsive to temperature, light, moisture
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S428/00—Stock material or miscellaneous articles
  • Y10S428/914—Transfer or decalcomania

Definitions

• TTP thermal transfer printing
• a heat-transferable dye is applied to a sheet-like substrate in the form of an ink, usually containing a polymeric or resinous binder to bind the dye to the substrate, to form a transfer sheet.
• This is then placed in contact with the material to be printed, (generally a film of polymeric material such as a polyester sheet) hereinafter called the receiver sheet and selectively heated in accordance with a pattern information signal whereby dye from the selectively heated regions of the transfer sheet is transferred to the receiver sheet and forms a pattern thereon in accordance with the pattern of heat applied to the transfer sheet.
• a dye for TTP is its thermal properties, brightness of shade, fastness properties, such as light fastness, and facility for application to the substrate in the preparation of the transfer sheet.
• the dye should transfer evenly, in proportion to the heat applied to the TTP sheet so that the depth of shade on the receiver sheet is evenly related to the heat applied and a true grey scale of coloration can be achieved on the receiver sheet.
• Brightness of shade is important in order to achieve as wide a range of shades with the three primary dye shades of yellow, magenta and cyan.
• the dye As the dye must be sufficiently mobile to diffuse rapidly from the transfer sheet to the receiver sheet at the temperatures reached, 150°C to 400°C, it is generally free from ionic and water-solubilising groups, and is thus not readily soluble in aqueous or water-miscible media, such as water and ethanol.
• aqueous or water-miscible media such as water and ethanol.
• suitable dyes are also not readily soluble in the solvents which are commonly used in, and thus acceptable to, the printing industry; for example, alcohols such as i -propanol, ketones such as methyl-ethylketone (MEK), methyl- i -butylketone (MIBK) and cyclohexanone, ethers such as tetrahydrofuran and aromatic hydrocarbons such as toluene.
• the dye can be applied as a dispersion in a suitable solvent, it has been found that brighter, glossier and smoother final prints can be achieved on the receiver sheet if the dye is applied to the substrate from a solution. In order to achieve the potential for a deep shade on the receiver sheet it is desirable that the dye should be readily soluble in the ink medium. It is also important that a dye which has been applied to a transfer sheet from a solution should be resistant to crystallisation so that it remains as an amorphous layer on the transfer sheet for a considerable time.
• the following combination of properties are highly desirable for a dye which is to be used in TTP:- Ideal spectral characteristics (narrow absorption curve with absorption maximum close to a subtractive primary shade e.g. those used in photography or printing). High tinctorial strength (extinction coefficient >40,000). Correct thermochemical properties (high thermal stability and good transferability with heat). High optical densities on printing. Good solubility in solvents acceptable to printing industry: this is desirable to produce solution coated dyesheets. Stable dyesheets (resistant to dye migration or crystallisation). Stable printed images on the receiver sheet (to heat and especially light).
• magenta shades having the desirable properties of (i) brightness, (ii) high tinctorial strength and (iii) high light fastness together with other desirable properties such as high optical densities and easy manufacture of dye sheets.
• a thermal transfer printing sheet comprising a substrate having a coating comprising: (1) an anthraquinone dye of the formula: wherein each of R1 and R2, independently, represents hydrogen or C1 ⁇ 4-alkyl and rings A and B are optionally substituted in the free positions by non-ionic groups, and (2) a monoazo dye of the formula: wherein each of R3 and R4, independently, represents C1 ⁇ 4-alkyl optionally substituted by halogen, cyano, phenyl, C1 ⁇ 4-alkoxy, C1 ⁇ 4-alkoxycarbonyl, C1 ⁇ 4-alkylcarbonyloxy, R6CONH-, R6NHCO- or R6NHCOO- in which R6 represents C1 ⁇ 4-alkyl or optionally substituted aryl; R5 represents hydrogen, halogen, C1 ⁇ 4-alkyl, C1 ⁇ 4-alkoxy, C1 ⁇ 4-alkylthio, beta-cyanoeth
• the coating present in the thermal transfer printing sheets of the invention may also optionally contain an anthraquinone dye of the formula: wherein R8 represents C5 ⁇ 12-alkyl, R9 represents H or C1 ⁇ 4-alkyl and rings E and F are optionally substituted in the free positions by non-ionic groups.
• the coating suitably comprises a binder together with one or more dyes of Formula I and one or more dyes of Formula II, optionally with the inclusion of one or more dyes of Formula VII.
• the ratio of binder to dyes is preferably at least 1:1 and more preferably from 1.5:1 to 4:1 in order to provide good adhesion between the dyes and the substrate and inhibit migration of the dyes during storage.
• R5 is selected from hydrogen, chlorine, methyl and acetylamino, especially hydrogen and methyl.
• Q is a radical of Formula III, especially a radical wherein V is methyl.
• Dyes of Formula II in which Q is a radical of Formula VI wherein n is 0 are also very valuable.
• the dyes of Formula I and Formula II are suitably employed in such proportions that the mixture contains from 5 to 40%, preferably from 10 to 30%, and especially from 15 to 25%, of dye of Formula II on a weight basis.
• the dye of Formula VII is usually present as a minor component, being less than 25% and more typically less than 10% of the total dye. Its presence enhances the solubility of the dye of Formula I and improves the dyesheet stability.
• the dyes of Formula I and Formula II have particularly good thermal properties giving rise to even prints on the receiver sheet, whose depth of shade is accurately proportional to the quantity of applied heat so that a true grey scale of coloration can be attained.
• the substrate may be any sheet material capable of with­standing the temperatures involved in TTP, up to 400°C over a period of up to 20 milliseconds (msec) yet thin enough to transmit heat applied on one side to the dye on the other side to effect transfer to a receiver sheet within such short periods, typically from 1-10 msec.
• suitable materials are polymers, e.g. polyester, polyacrylate, polyamide, cellulosic and polyalkylene films, metallised forms thereof, including co-polymer and laminated films, especially laminates incorporating a polyester receptor layer on which the dye is deposited and also thin, high quality paper with even thickness and smooth surface, such as capacitor paper.
• Heating in the selected areas may be effected by contact with heating elements, heated to 200-400°C, preferably 200-360°C, over periods of 2 to 10 msec, whereby the dye is heated to 150-300°C, depending on the time of exposure, and thereby caused to transfer, mainly by diffusion from the transfer to the receiver sheet.
• Good contact between dye and receiver sheet at the point of application is essential to effect transfer.
• the density of the printed image is related to the time period for which the transfer sheet is heated.
• Such a receptive layer which may be applied by co-extrusion or solution coating techniques, may comprise a thin layer of a modified polyester or a different polymeric material which is more permeable to the dye than the PET substrate. While the nature of the receptive layer will affect to some extent the depth of shade and quality of the print obtained it has been found that the combination of dyes of Formula I and Formula II give particularly strong and good quality prints (e.g. fast to light, heat and storage) on any specific transfer or receiver sheet, compared with other dyes of similar structure which have been proposed for thermal transfer printing. The design of receiver and transfer sheets is discussed further in EP 133,011 and EP 133012.
• a solution comprising 0.4g 1-amino-4-hydroxy-2-phenoxy-­anthraquinone (Dye A), 0.lg N-(2-acetoxyethyl)-4-[(4-cyano-­3-methylisothioazol-5-yl)azo]-N-ethyl-3-methylaniline (Dye B), 1.0g ethyl cellulose T10 and 8.5g tetrahydrofuran (THF) was prepared by shaking together the components until a homogeneous solution was obtained.
• Dye A 1-amino-4-hydroxy-2-phenoxy-­anthraquinone
• Dye B 0.lg N-(2-acetoxyethyl)-4-[(4-cyano-­3-methylisothioazol-5-yl)azo]-N-ethyl-3-methylaniline
• Dye B 1.0g ethyl cellulose T10 and 8.5g tetrahydrofuran
• a transfer sheet was prepared by applying Ink 1 to a sheet of 6 micron thick polyethylene terephthalate using a wire-wound metal Mayer-bar (K3) to produce a layer of ink on the surface of the sheet.
• the ink was dried with hot air - TS 1.
• a sample of TS 1 was sandwiched with a receiver sheet, comprising a composite structure based on a white polyester base having a copolyester receptor surface with the receptor surface of the latter in contact with the printed surface of the former.
• the sandwich was placed on the drum of a transfer printing machine and passed over a matrix of closely-spaced pixels which were selectively heated in accordance with a pattern information signal to 300-350°C over 2 to 10 msec, whereby a quantity of dye, at the point on the transfer sheet in contact with a pixel while it is hot, in proportion to the heating period, was transfered from the transfer sheet to the receiver sheet. After passage over the array of pixels the transfer sheet was separated from the receiver sheet.
• a transfer sheet was prepared in the same manner as Example 1 using Ink 2 in place of Ink 1 - TS 2.
• a corresponding receiver sheet was prepared as described in Example 1.
• Example 1 Prepared as in Example 1 using Inks 3-5 to give TS 3-5.
• Corresponding receiver sheets were prepared as described in Example 1.
• the quality of the printed impression on the receiver sheet was assessed in respect of reflection density of colour (printing time 10 msec) by means of a Sakura Digital densitometer.
• a solution comprising 0.445g of Dye A, 0.055g of Dye B, 1.0g ethyl hydroxyethyl cellulose and 8.5g tetrahydrofuran was prepared by shaking together the compounds until a homogeneous solution was obtained.
• Transfer sheets (TS 6-8) were prepared in the same manner as for Example 1 using Inks 6-8.
• Inks were prepared as follows: 9A 9B 9C Dye A 0.5 0.43 - Azo dye - 0.07 0.5 EHEC 0.5 0.5 0.5 THF 9.0 9.0 9.0
• the azo dye used was N,N-diethyl-4-[(3-methylthio-­1,2,4-thiadiazol-5-yl)azo]-3-methylaniline.
• Inks were prepared as follows: 10A 10B Dye A 0.437 - Azo dye 0.063 0.1 EHEC 1.0 0.2 THF 8.5 9.7
• the azo dye used was N,N-diethyl-4-[(1-cyanomethyl-­3,4-dicyanopyrazol-5-yl)azo]-3-methylaniline.
• Inks were prepared as follows: 11A 11B Dye A 0.417 - Azo dye 0.083 0.5 EHEC 1.0 1.0 THF 8.5 8.5
• the azo dye used was N-benzyl-N-ethyl-4-[(4-cyano-3-methyl-­isothiazol-5-yl)azo]-3-acetylaminoaniline.
• Inks were prepared as follows: 12A 12B Dye A 0.417 - Azo dye 0.083 0.1 EHEC 1.0 0.2 THF 8.5 9.7
• the azo dye used was N-(2-acetylaminoethyl)-4-[(4-cyano-­3-methylisothiazol-5-yl)azo]-N-ethylaniline.
• Inks were prepared as follows: 13A 13B Dye A 0.417 - Azo dye 0.083 0.1 EHEC 1.0 0.2 THF 8.5 9.7
• the azo dye used was N,N-diethyl-4-[(4-cyano-­3-methylisothiazol-5-yl)azo]-3-chloroaniline.
• An ink comprising 0.445 part of Dye A, 0.055 part of Dye B, 0.05 part of 1-amino-2-[4-(1,1,3,3-tetra­methylbutyl)phenoxy]-4-hydroxyanthraquinone, 1.0g of ethyl hydroxyethyl cellulose and 8.5g of tetrahydrofuran.
• a transfer sheet was prepared from this ink as described in Example 1.
• the corresponding receiver sheet had an optical density of 2.08.

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• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Thermal Transfer Or Thermal Recording In General (AREA)
• Inks, Pencil-Leads, Or Crayons (AREA)
• Adhesives Or Adhesive Processes (AREA)

Priority Applications (1)

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Publications (2)

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ID=10625262

Family Applications (1)

Country Status (9)

Cited By (4)

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Citations (2)

Family Cites Families (4)

• 1987
  • 1987-10-13 GB GB878724028A patent/GB8724028D0/en active Pending
• 1988
  • 1988-09-20 DE DE8888308674T patent/DE3866503D1/de not_active Expired - Fee Related
  • 1988-09-20 GB GB888822023A patent/GB8822023D0/en active Pending
  • 1988-09-20 AT AT88308674T patent/ATE69769T1/de not_active IP Right Cessation
  • 1988-09-20 ES ES198888308674T patent/ES2028295T3/es not_active Expired - Lifetime
  • 1988-09-20 EP EP88308674A patent/EP0312211B1/de not_active Expired - Lifetime
  • 1988-10-04 US US07/252,988 patent/US4829048A/en not_active Expired - Lifetime
  • 1988-10-11 KR KR1019880013241A patent/KR890006406A/ko not_active IP Right Cessation
  • 1988-10-13 JP JP63256090A patent/JP2801221B2/ja not_active Expired - Lifetime
• 1991
  • 1991-11-28 GR GR91400628T patent/GR3003210T3/el unknown

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